I have Viconia in my party on my current playthrough. She has quite a nice Dexterity stat. I was wandering how good her AC can be. I was able to drop it to -15 using drow gear, as shown on the screenshot. Can someone outbid me please? :)

Is this vanilla game? I play modded BG2 with Spell/Item Revisions and in my last playthrough I buffed my main paladin's AC to -24 which is the lowest value possible, to tank Firkraag. It would be -18 without any buff. That was without the Drow armor.

EDIT: I checked with vanilla game. I managed to get that character to -17 AC without any buff. Needed the Drow full plate and the Boots of Phasing though.

The easiset way to get low AC is to use the Blade's Defensive Spin, I believe; it's capable of lowering your AC by something like 10 points. Combine that with other ways to improve AC, and reaching -24 should be quite doable.

With that said, AC turns out not to matter much at Throne of Bhaal levels; in fact, unless you can get your AC really low, it is best to ignore AC entirely. At this point, armor is useless unless it provides a special effect.

In BG2, if you actually want a character who can tank, I believe your best option is actually a Sorcerer with a good spell selection (Stoneskin, Protection from Magical Weapons, other defensive spells). If you want someone who can fight decently, it turns out that Aerie is not a bad choice; with the help of the right spells and magic items, she can hold her own in melee.

(I don't remember whether the kill sword (use the cheat CLUAConsole:CreateItem("killsw01") to get it) would lower your AC, but it does make you invincible; then again, I would say that this exercise is more fun if you don't allow the use of the cheat console or mods.)

Or a cleric-mage. The people who say "Aerie is not that good since her INT and WIS are both so-so" clearly have never had her solo a host of balors and glabrezus, hitting for avg. 30 dmg per hit, while being invulnerable to practically everything.

And getting 3 or 4 attacks per round. (Polymorph Self + sequencers to replace those monster weapons with weapons that get used up, and Draw Upon Holy Might to raise Strength to at least 19; sequencers with cleric spells are fun, even Minor Sequencer is suddenly useful).

In any case, I can distinguish between pure tanks whose sole role is to survive (Sorcerers work well here) and fighter-tanks who are meant to be able to deal damage while tanking (cleric/mage works here, or you could try fighter/cleric/mage).

(Also, I believe Aerie is the only recruitable character who can restore low-level spells to the entire party without using any consumables (or having a Projected Image use them) or piggybacking off somebody else's spell.)

That's right, Jaheira is a decent tank. I had her in my party during all of my previous playthroughs. I decided it's time for a change this time. I'm not using Viconia as a tank however. Too low HP, as you pointed that out. Yes, it's vanilla game. It's probably the lowest AC I managed to reach. I had no idea that there's a technical limit at -24. That's quite a nice skill. I never had a bard in my party. Maybe I'll take Haer'Dalis with me on my next playthrough. :) My main character is a Dragon Disciple. In fact Sorcerer is my favorite class. He does indeed a good job as a tank with all those buffs from spells. Too bad that there's no Sorcerer companion in the vanilla game. As for Aerie, I never liked her. Too fragile for a good Cleric, too slow spell progression for a good mage. You can counter the first, but she still struggles as the second.

So you can use sequencers with cleric spells? That opens some interesting possibilities...

Yes, and it is a nice synergy between those two classes. Some nice uses:
* Some low level cleric spells (Bless comes to mind) have long casting times and short durations; sequencers allow you to cast them instantly.
* You can't cast spells while polymorphed, but you *can* use special abilities, including sequencers. (Draw Upon Holy Might to boost strength to 19+, and Spiritual Hammer to overwrite the natural weapon are two of my favorites.)
* At high levels, later in Thoone of Bhaal, the lack of Mass Heal in this game limits your (reliable) multi-target healing ability. With a sequencer, just put 3 Mass Cures in one and you have a decent substitute (that's even instant cast; nice for emergencies). (Note that sequencers don't work well with single-target healing spells unless you cast them on yourself, unfortunately.)

I have criticized this game in other threads, but one thing it does that I *llike* is that every pair of classes has some multi-class synergy; this is the Cleric/Mage one. (Yes, even odd combinations like Cleric/Thief (DUHM boosts Dexterity, which affects thief skills, for example).)

Yeah you can. That's why a cleric/mage is about the most versatile character, since they can handle pretty much any kind of situation. I like to put spells like Holy Power, Champion's Strength, Righteous Fury, Mislead, Stoneskin, Mirror Image, Fire Shield, etc. into a Spell Sequencer or a Spell Trigger (late game). Then basically you have a button that instantly transforms the cleric/mage into an auto-attack monster. You can create quite a few interesting "combos" by combining the right spells together. A Spell Trigger that fires a triple Bolt of Glory is pretty much an instant kill button against any demon, since Bolt of Glory ignores spell resistance.

Versatility is the main reason why I like having Aerie in the party.

Oooh, I'll have to try that! I didn't know that Bolt of Glory ignores Magic Resistance.

You could outbid yourself by having her don the Cloak of the Sewers and the Ring of Earth Control (?...the one you get during Nalia's quest) for a -2 total AC boost.

Also, I'm not sure which shield that is, but perhaps there is a better one somewhere?

Of course, losing that Drow armour will inevitably drop her AC back down anyway.

EDIT: oh, and you could arm her with the Defender of Easthaven for another -2 AC, I think.

In the classic edition (vanilla), if your concern is preventing physical damage, there's a more powerful strategy; cast Armor of Faith then use the Cloak of Sewers to turn into a sewer rat; this will give you at least 100% resistance to physical attacks, causing them to not damage the character and possibly even heal.

One major drawback is that this only protects against damage; vampires and mind flayers are still dangerous (but then again, even Mirror Image is of no help there). Another is that there is the small problem of actually doing damage.

(Yes, for some reason the sewer rats have high physical resistance; I would have expected them to have low or no physical resistance and good AC instead.) It does, of course, have the downside that the character can't move while the ability is in effect. (I am not sure if there's a way to get around this restriction; knowing the game, it's probably possible in the vanilla classic edition, but I don't know how.)

In the vanilla game you could cheat around this using things like the Free Action ring.
I think it has been fixed in the Enhanced Edition.

In ToB you can easily get -20 AC.